// Copyright (c) 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/metrics/persistent_sample_map.h"

#include <memory>

#include "base/memory/ptr_util.h"
#include "base/metrics/persistent_histogram_allocator.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {
namespace {

    std::unique_ptr<PersistentHistogramAllocator> CreateHistogramAllocator(
        size_t bytes)
    {
        return WrapUnique(new PersistentHistogramAllocator(
            WrapUnique(new LocalPersistentMemoryAllocator(bytes, 0, ""))));
    }

    std::unique_ptr<PersistentHistogramAllocator> DuplicateHistogramAllocator(
        PersistentHistogramAllocator* original)
    {
        return WrapUnique(
            new PersistentHistogramAllocator(WrapUnique(new PersistentMemoryAllocator(
                const_cast<void*>(original->data()), original->length(), 0,
                original->Id(), original->Name(), false))));
    }

    TEST(PersistentSampleMapTest, AccumulateTest)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta;
        PersistentSampleMap samples(1, allocator.get(), &meta);

        samples.Accumulate(1, 100);
        samples.Accumulate(2, 200);
        samples.Accumulate(1, -200);
        EXPECT_EQ(-100, samples.GetCount(1));
        EXPECT_EQ(200, samples.GetCount(2));

        EXPECT_EQ(300, samples.sum());
        EXPECT_EQ(100, samples.TotalCount());
        EXPECT_EQ(samples.redundant_count(), samples.TotalCount());
    }

    TEST(PersistentSampleMapTest, Accumulate_LargeValuesDontOverflow)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta;
        PersistentSampleMap samples(1, allocator.get(), &meta);

        samples.Accumulate(250000000, 100);
        samples.Accumulate(500000000, 200);
        samples.Accumulate(250000000, -200);
        EXPECT_EQ(-100, samples.GetCount(250000000));
        EXPECT_EQ(200, samples.GetCount(500000000));

        EXPECT_EQ(75000000000LL, samples.sum());
        EXPECT_EQ(100, samples.TotalCount());
        EXPECT_EQ(samples.redundant_count(), samples.TotalCount());
    }

    TEST(PersistentSampleMapTest, AddSubtractTest)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator1 = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta1;
        PersistentSampleMap samples1(1, allocator1.get(), &meta1);
        samples1.Accumulate(1, 100);
        samples1.Accumulate(2, 100);
        samples1.Accumulate(3, 100);

        std::unique_ptr<PersistentHistogramAllocator> allocator2 = DuplicateHistogramAllocator(allocator1.get());
        HistogramSamples::Metadata meta2;
        PersistentSampleMap samples2(2, allocator2.get(), &meta2);
        samples2.Accumulate(1, 200);
        samples2.Accumulate(2, 200);
        samples2.Accumulate(4, 200);

        samples1.Add(samples2);
        EXPECT_EQ(300, samples1.GetCount(1));
        EXPECT_EQ(300, samples1.GetCount(2));
        EXPECT_EQ(100, samples1.GetCount(3));
        EXPECT_EQ(200, samples1.GetCount(4));
        EXPECT_EQ(2000, samples1.sum());
        EXPECT_EQ(900, samples1.TotalCount());
        EXPECT_EQ(samples1.redundant_count(), samples1.TotalCount());

        samples1.Subtract(samples2);
        EXPECT_EQ(100, samples1.GetCount(1));
        EXPECT_EQ(100, samples1.GetCount(2));
        EXPECT_EQ(100, samples1.GetCount(3));
        EXPECT_EQ(0, samples1.GetCount(4));
        EXPECT_EQ(600, samples1.sum());
        EXPECT_EQ(300, samples1.TotalCount());
        EXPECT_EQ(samples1.redundant_count(), samples1.TotalCount());
    }

    TEST(PersistentSampleMapTest, PersistenceTest)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator1 = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta12;
        PersistentSampleMap samples1(12, allocator1.get(), &meta12);
        samples1.Accumulate(1, 100);
        samples1.Accumulate(2, 200);
        samples1.Accumulate(1, -200);
        samples1.Accumulate(-1, 1);
        EXPECT_EQ(-100, samples1.GetCount(1));
        EXPECT_EQ(200, samples1.GetCount(2));
        EXPECT_EQ(1, samples1.GetCount(-1));
        EXPECT_EQ(299, samples1.sum());
        EXPECT_EQ(101, samples1.TotalCount());
        EXPECT_EQ(samples1.redundant_count(), samples1.TotalCount());

        std::unique_ptr<PersistentHistogramAllocator> allocator2 = DuplicateHistogramAllocator(allocator1.get());
        PersistentSampleMap samples2(12, allocator2.get(), &meta12);
        EXPECT_EQ(samples1.id(), samples2.id());
        EXPECT_EQ(samples1.sum(), samples2.sum());
        EXPECT_EQ(samples1.redundant_count(), samples2.redundant_count());
        EXPECT_EQ(samples1.TotalCount(), samples2.TotalCount());
        EXPECT_EQ(-100, samples2.GetCount(1));
        EXPECT_EQ(200, samples2.GetCount(2));
        EXPECT_EQ(1, samples2.GetCount(-1));
        EXPECT_EQ(299, samples2.sum());
        EXPECT_EQ(101, samples2.TotalCount());
        EXPECT_EQ(samples2.redundant_count(), samples2.TotalCount());

        samples1.Accumulate(-1, -1);
        EXPECT_EQ(0, samples2.GetCount(3));
        EXPECT_EQ(0, samples1.GetCount(3));
        samples2.Accumulate(3, 300);
        EXPECT_EQ(300, samples2.GetCount(3));
        EXPECT_EQ(300, samples1.GetCount(3));
        EXPECT_EQ(samples1.sum(), samples2.sum());
        EXPECT_EQ(samples1.redundant_count(), samples2.redundant_count());
        EXPECT_EQ(samples1.TotalCount(), samples2.TotalCount());

        EXPECT_EQ(0, samples2.GetCount(4));
        EXPECT_EQ(0, samples1.GetCount(4));
        samples1.Accumulate(4, 400);
        EXPECT_EQ(400, samples2.GetCount(4));
        EXPECT_EQ(400, samples1.GetCount(4));
        samples2.Accumulate(4, 4000);
        EXPECT_EQ(4400, samples2.GetCount(4));
        EXPECT_EQ(4400, samples1.GetCount(4));
        EXPECT_EQ(samples1.sum(), samples2.sum());
        EXPECT_EQ(samples1.redundant_count(), samples2.redundant_count());
        EXPECT_EQ(samples1.TotalCount(), samples2.TotalCount());
    }

    TEST(PersistentSampleMapIteratorTest, IterateTest)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta;
        PersistentSampleMap samples(1, allocator.get(), &meta);
        samples.Accumulate(1, 100);
        samples.Accumulate(2, 200);
        samples.Accumulate(4, -300);
        samples.Accumulate(5, 0);

        std::unique_ptr<SampleCountIterator> it = samples.Iterator();

        HistogramBase::Sample min;
        HistogramBase::Sample max;
        HistogramBase::Count count;

        it->Get(&min, &max, &count);
        EXPECT_EQ(1, min);
        EXPECT_EQ(2, max);
        EXPECT_EQ(100, count);
        EXPECT_FALSE(it->GetBucketIndex(NULL));

        it->Next();
        it->Get(&min, &max, &count);
        EXPECT_EQ(2, min);
        EXPECT_EQ(3, max);
        EXPECT_EQ(200, count);

        it->Next();
        it->Get(&min, &max, &count);
        EXPECT_EQ(4, min);
        EXPECT_EQ(5, max);
        EXPECT_EQ(-300, count);

        it->Next();
        EXPECT_TRUE(it->Done());
    }

    TEST(PersistentSampleMapIteratorTest, SkipEmptyRanges)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator1 = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta1;
        PersistentSampleMap samples1(1, allocator1.get(), &meta1);
        samples1.Accumulate(5, 1);
        samples1.Accumulate(10, 2);
        samples1.Accumulate(15, 3);
        samples1.Accumulate(20, 4);
        samples1.Accumulate(25, 5);

        std::unique_ptr<PersistentHistogramAllocator> allocator2 = DuplicateHistogramAllocator(allocator1.get());
        HistogramSamples::Metadata meta2;
        PersistentSampleMap samples2(2, allocator2.get(), &meta2);
        samples2.Accumulate(5, 1);
        samples2.Accumulate(20, 4);
        samples2.Accumulate(25, 5);

        samples1.Subtract(samples2);

        std::unique_ptr<SampleCountIterator> it = samples1.Iterator();
        EXPECT_FALSE(it->Done());

        HistogramBase::Sample min;
        HistogramBase::Sample max;
        HistogramBase::Count count;

        it->Get(&min, &max, &count);
        EXPECT_EQ(10, min);
        EXPECT_EQ(11, max);
        EXPECT_EQ(2, count);

        it->Next();
        EXPECT_FALSE(it->Done());

        it->Get(&min, &max, &count);
        EXPECT_EQ(15, min);
        EXPECT_EQ(16, max);
        EXPECT_EQ(3, count);

        it->Next();
        EXPECT_TRUE(it->Done());
    }

// Only run this test on builds that support catching a DCHECK crash.
#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)) && GTEST_HAS_DEATH_TEST
    TEST(PersistentSampleMapIteratorDeathTest, IterateDoneTest)
    {
        std::unique_ptr<PersistentHistogramAllocator> allocator = CreateHistogramAllocator(64 << 10); // 64 KiB
        HistogramSamples::Metadata meta;
        PersistentSampleMap samples(1, allocator.get(), &meta);

        std::unique_ptr<SampleCountIterator> it = samples.Iterator();

        EXPECT_TRUE(it->Done());

        HistogramBase::Sample min;
        HistogramBase::Sample max;
        HistogramBase::Count count;
        EXPECT_DEATH(it->Get(&min, &max, &count), "");

        EXPECT_DEATH(it->Next(), "");

        samples.Accumulate(1, 100);
        it = samples.Iterator();
        EXPECT_FALSE(it->Done());
    }
#endif
    // (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)) && GTEST_HAS_DEATH_TEST

} // namespace
} // namespace base
